Electrical potentials between stent-grafts made from different metals induce negligible corrosion.

OBJECTIVE: Evaluation of the risk of galvanic corrosion in various stent-grafts in current practice, when devices with unmatched alloy compositions are deployed together. METHOD: Five nitinol (NT) and two steel (SS) stent-grafts produced by different companies were used in different combinations to create 21 samples (NT:NT, n = 10; NT:SS, n = 10; SS:SS, n = 1). Electric potential was measured between the metal couplings after immersion in 0.9% NaCl at a temperature of 37 °C. Subsequently, the same samples were incubated for 24 months in 0.9% NaCl at 37-39 °C under hermetic conditions and examined under a scanning electron microscope in order to search for any evidence of corrosion. RESULTS: Electric potentials between different metals alloys were found (means: NT:SS, 181 µV; NT:NT, 101 µV; SS:SS, 160 µV). The mean electrical potential between stainless steel and nitinol samples was significantly higher than between NT:NT couplings (p < .001). During the final scanning electron microscope examination, only one spot of pitting corrosion (>10 µm) on a nitinol surface was found (associated with previous mechanical damage) in an NT:SS sample after 24 months of incubation in vitro and no sign of mechanical failure of the wires was found. CONCLUSION: Direct contact between the stainless steel and the nitinol alloys does indeed create electrical potential but with a minimal risk of galvanic corrosion. No evidence was found for significant galvanic corrosion when two endovascular implants (stent-grafts) made from different metal composition were used in the same procedure.

Soy isoflavones administered pre- and postnatally may affect the ERα and ERß expression and elements' content in bones of mature male rats.

The aim of this study was to assess the influence of soy isoflavones, administered pre- and later postnatally, on the estrogen receptor α (ERα) and ß (ERß) expression in bones and to examine the mineral metabolism of the skeletal system in male rats. In bones, ERs were examined with an immunohistochemical method; in blood, estradiol with chemiluminescence immunoassay and in blood and bones, calcium and magnesium with atomic absorption spectrometry and fluorides with a potentiometric method were examined. Decreased immunoexpression of ERα and the increased intensity of immunofluorescence of ERß in osteocytes in the femur of experimental rats were observed. In the serum of treated rats, a significantly higher concentration of estradiol and lower calcium were observed. The content of magnesium and fluoride were significantly higher in the bones of the examined animals. The data presented show that pre- and postnatal supplementation of male rats with soy isoflavones may considerably increase the concentration of estrogens in serum, with a concurrent effect on the mineral composition of bones.

Altered energy status of primary cerebellar granule neuronal cultures from rats exposed to lead in the pre- and neonatal period.

This paper examines the effect of pre- and neonatal exposure of rats to lead (0.1% lead acetate in drinking water, resulting in rat offspring whole blood lead concentration (Pb-B) 4µg/dL) on the energy status of neuronal mitochondria by measuring changes in ATP, ADP, AMP, adenosine, TAN concentration, adenylate energy charge value (AEC) and mitochondrial membrane potential in primary cerebellar granule neurons (CGC) in dissociated cultures. Fluorescence studies were performed to imaging and evaluate mitochondria mass, mitochondrial membrane potential, intracellular and mitochondrial reactive oxygen species (ROS) production. The Na(+)/K(+) ATPase activity in intact CGC was measured spectrophotometrically. Our data shows that pre- and neonatal exposure of rats to Pb, even below the threshold of whole blood Pb value considered safe for people, affects the energy status of cultured primary cerebellar granule neurons through a decrease in ATP and TAN concentrations and AEC value, inhibition of Na(+)/K(+) ATPase, and increase in intracellular and mitochondrial ROS concentration. These observations suggest that even these low levels of Pb are likely to induce important alterations in neuronal function that could play a role in neurodegeneration.

Elastin degradation within the abdominal aortic aneurysm wall--relationship between intramural pH and adjacent thrombus formation.

BACKGROUND: The natural history of abdominal aortic aneurysm (AAA) is wall remodelling potentially leading to a final rupture. The pathogenesis of AAA appears to be multifactorial. The aim of this pilot prospective study was to assess the relationship between the thickness of the thrombus within the abdominal aortic aneurysm, intramural pH and local elastin degradation. MATERIALS AND METHODS: The AAA size, intraluminal thrombus (ILT) morphology and location were evaluated in 206 consecutive patients. Thirty patients with large AAA (aortic diameter > or = 50 mm) and adjacent ILT with the thinnest part < or = 10 mm and thickest > or = 25 mm, measured in the region of the maximum diameter of AAA, were included for further study. During AAA surgery intramural pH measurements were performed and specimens taken from both thin thrombus-covered and thick thrombus-covered wall for computerized morphometric analysis. RESULTS: Mean intramural pH value was 7.21 +/- 0.18 for the wall covered by thick ILT and 7.64 +/- 0.10 for the thin one (P < 0.001). Computerized morphometric analysis demonstrated that elastin fibres in the thin thrombus-covered wall were decreased in size (for width--P < 0.0001, for length--P < 0.13), irregularly orientated (P < 0.000001) and the amount of fibres was reduced when compared to the wall covered by thick ILT (P < 0.0004). CONCLUSION: A strong relationship between intramural pH and elastin net destruction suggests that the local alkaline status within the thin thrombus-covered part of the aneurysm wall is contributing to the elastinolytic process.

Abdominal aortic aneurysm: association between haptoglobin phenotypes, elastase activity, and neutrophil count in the peripheral blood.

To investigate the role of genetic factors on susceptibility to atherosclerotic arterial disease, the influence of haptoglobin phenotypes (Hp) on serum elastase activity, neutrophil count, and elastin concentration in the aorta was measured in patients with abdominal aortic aneurysm (AAA; n=52) and aortoiliac atherosclerotic occlusive disease (AOD; n=37). Findings (serum elastase activity, peripheral blood neutrophil count) were compared to a control group (CG) of 37 subjects without atherosclerosis. Hp phenotyping performed by starch-gel electrophoresis produced a haptoglobin-hemoglobin complex of three phenotypes: Hp1-1, Hp2-2, and Hp2-1. Distribution of Hp phenotypes was similar in the three study groups (AAA, AOD, CG). Significant increases in serum elastase activity and neutrophil count was measured in Hp2-1 phenotype of AAA patients. Although the aorta wall of aneurysm patients contained less (p<0.001) elastin than that of AOD patients, no significant difference of aorta elastin concentration between the three Hp phenotypes, including Hp2-1, was measured. The postulated association of AAA susceptibility with Hp2-1 phenotype was supported by the study data that demonstrated an increase in serum elastase activity in patients undergoing AAA repair.

[The pathogenesis of abdominal aortic aneurysm and polymorphism of haptoglobin and inflammatory factor]. / Patogeneza tetniaka aorty brzusznej a polimorfizm haptoglobiny i czynnik zapalny.

52 patients were operated on for abdominal aortic aneurysm and 38 for aortic occlusion disease. Haptoglobin (Hp) phenotypes were determined in all these patients. Hp and C-reactive protein (CRP) concentrations were determined in each phenotype. On the basis of the statistical analysis the highest percentage of elevated CRP concentrations was found in patients with abdominal aortic aneurysm and phenotype Hp 2-1.

[How quickly does an abdominal aortic aneurysm grow?]. / Jak szybko powieksza sie tetniak aorty brzusznej?

86 patients with Abdominal Aortic Aneurysm was assessed by abdominal ultrasound with respect to growth rate. For aneurysms with diameter 3-4 cm, mean growth rate was 0.215 mm per month, for aneurysms 4-5 cm was 0.33 mm per month and for aneurysms with AP diameter bigger than 50 mm the mean growth rate was 0.78 mm per month.